Classical cannabinoids such as the marijuana derived cannabinoid Δ9-tetrahydrocannabinol, (Δ9-THC) produce their pharmacological effects through interaction with specific cannabinoid receptors in the body. So far, two cannabinoid receptors have been characterized: CB1, a central receptor found in the mammalian brain and peripheral tissues and CB2, a peripheral receptor found only in the peripheral tissues. Compounds that are agonists or antagonists for one or both of these receptors have been shown to provide a variety of pharmacological effects.
There is considerable interest in developing cannabimimetic compounds possessing high affinity for one of the CB1 or CB2 receptors. Such compounds may offer a rational therapeutic approach to a variety of disease conditions. One class of cannabimimetic compound encompasses indole derivatives such as the well-known aminoalkylindoles represented by WIN 55212-2 {(R)-(+)-[2,3-dihydro-5-methyl-3-[(4-morpholinyl)methyl]-pyrrolo[1,2,3-de]-1,4-benzoxazin-6-yl](1-napthalenyl)methanone}. Aminoalkylindoles of this type typically have a carbon linked alkylheterocyclic substituent at the indole-1 position, which is believed to be important for their cannabimimetic activities. These known materials are not selective for preferential activation of one of the CB1 or CB2 receptors.